Widely renowned as one of the most successful FBI Informants, Joseph D. Pistone aka. "Donnie Brasco" (his undercover alias) was an undercover FBI agent who infiltrated New York's powerful Bonnano Mafia family from 1976-1981.

The Bonnano Family at the time was headed by Carmine Galante, who through the Pizza Connection, became the single largest importer of heroin into the United States in the 1970's. The FBI was determined to learn the particulars of his smuggling operation, and chose Joseph Pistone to pose undercover as a jewel thief.

For 6 years, FBI agent Joseph Pistone lived a double life undercover, and slowly caught the attention and admiration of top Bonnano "Capo" (Captain) Dominick Napolitano, who along with Bonnano family "soldier", Benjamin Ruggiero, grew to trust Pistone so much they revealed to him many important clues about the heroin distribution network.

After 6 years within the ranks of the Bonnanos, Pistone had fooled his close associates so well they had proposed to make Pistone a full member of the Bonnano family, or a "Made Man".
The only catch was Pistone was asked to execute Anthony Indelicato, who was suspected to have been involved in the murder of the former Bonnano family boss Carmine Galante.

This signalled the end of the FBI's undercover operation within the Bonnano family.

Two days after Pistone was proposed to undertake a "hit" (or contract killing), FBI Agents informed Napolitano and Ruggiero that their long-time friend was an FBI agent.

Johnny Depp plays Donnie Brasco in the film of the same name.

The real Joseph Pistone left the FBI and now works as a free-lance consultant on organized crime for law enforcement agencies.

The evidence collected by Pistone led to over 200 indictments and over 100 convictions of Mafia members.

Dominic "Sonny Black" Napolitano was killed by the Bonnanos in 1981 for having allowed Pistone to infiltrate the family.

Usually used when a friend brings along another "friend" into your group to hang out. you and the other people normally in your crew are not to sure about the credentials of this "new friend". you ask around to your buddies if anyone knows this new guy (most likely already forgetting this new guys name) hence calling him "donnie brasco". as not to mention to much inside info/gossip as no one in your group is aware on who or what this guy is all about.

"hey Jimmy... whats up with "donnie brasco" over there?"

"i dunno Tommy.. Frankie brought him by tonight. you know anything about this guy?"